diff --git a/R/process_directory.R b/R/process_directory.R
index 118c0d5..d01b9dd 100644
--- a/R/process_directory.R
+++ b/R/process_directory.R
@@ -24,20 +24,7 @@ process_directory <- function(
   logger::log_info("Preparing metadata JSON file.")
   if (validate) {
     logger::log_info("Validating output.")
-    sch <- jsonvalidate::json_schema[["new"]](
-      schema = schema_file,
-      strict = TRUE,
-      engine = "ajv"
-    )
-    summaries_json <- jsonlite::prettify(
-      sch[["serialise"]](all_summaries)
-    )
-    json_is_valid <- sch[["validate"]](summaries_json, verbose = TRUE)
-    if (json_is_valid) {
-      logger::log_debug("JSON is valid.")
-    } else {
-      logger::log_error("JSON is not valid.")
-    }
+    summaries_json <- schema_serialize(all_summaries)
   } else {
     logger::log_warn("Skipping JSON validation.")
     summaries_json <- jsonlite::toJSON(
diff --git a/R/schema_serialize.R b/R/schema_serialize.R
new file mode 100644
index 0000000..0b450d6
--- /dev/null
+++ b/R/schema_serialize.R
@@ -0,0 +1,38 @@
+schema_serialize <- function(
+  object,
+  schema_file = system.file(
+    "extdata", "schema", "metadata.json",
+    package = "workflow.portfolio.parsing"
+  ),
+  reference = NULL
+) {
+  sch <- jsonvalidate::json_schema[["new"]](
+    schema = readLines(schema_file),
+    strict = TRUE,
+    engine = "ajv",
+    reference = reference
+  )
+  json <- sch[["serialise"]](object)
+  json_is_valid <- sch[["validate"]](json, verbose = TRUE)
+  if (json_is_valid) {
+    logger::log_trace("JSON is valid.")
+  } else {
+    json_errors <- attributes(json_is_valid)[["errors"]]
+    logger::log_warn(
+      "Portfolio metadata could not be validated against ",
+      "JSON schema: \"", schema_file, "\"."
+    )
+    logger::log_trace(
+      logger::skip_formatter(paste("JSON string: ", json))
+    )
+    logger::log_trace("Validation errors:")
+    for (i in seq(from = 1L, to = nrow(json_errors), by = 1L)) {
+      logger::log_trace(
+        "instancePath: ", json_errors[i, "instancePath"],
+        " message: ", json_errors[i, "message"]
+      )
+    }
+    warning("Portfolio metadata could not be validated against schema.")
+  }
+  return(json)
+}